The present invention relates generally to noise reduction devices for automotive vehicles and more particularly to a mechanism which may be utilized at the rear axle of the vehicle to reduce unpleasant noise which may occur in the vehicle passenger compartment. More specifically, the invention is directed to reducing or eliminating axle noise in a vehicle of the 4-link rear suspension type.
In vehicles of this type, the vibrations excited by the rear axle pinion and ring gears during operation of the vehicle are amplified by resonance occurring in such parts as the driveline or the rear axle housing of the vehicle. These vibrations is then transferred to the body-frame by such parts as the lower control arm, the upper control arm or the lateral control arm, thereby generating a disagreeable noise within the passenger compartment of the vehicle.
In order to reduce such noise, several methods have been proposed. An example of one such method involves changing the resonance point of the driveline of the vehicle or of the axle housing or other similar parts. Other proposals have included reducing the vibration level at the resonance point of the rear axle housing by a dynamic damper. However, it has been found that all such proposals do not sufficiently satisfy the noise reduction requirements.
The present invention is aimed toward providing a more effective means for reducing axle noise in the vehicle compartment.